https://insideevs.com/news/755990/parallel-hybrids-versus-power-split-hybrids/
Five different types of hybrids exist: mild hybrids, plug-in hybrids, parallel hybrids, series hybrids (also known as range extenders or E-REVs) and power-split hybrids, which are alternatively called series-parallel hybrids. You’ll also see plenty of people confusing these terms, like when they refer to any hybrid without a plug as a “mild hybrid.” In reality, that term means a car with a 48-volt starter generator, which generally just uses an electric motor as a torque fill or efficiency booster. Traditional hybrids can typically power the wheels on electricity alone for a stint, and come in parallel, series and power-split types.
The Hyundai Santa Fe Hybrid is one example of a parallel hybrid. A classic example of a series-parallel or power-split hybrid is the Toyota Prius. They have plenty in common but also have considerable differences in the type of components they use and how they function.
A new video from Paul Turnbull, the lead engineer at Munro & Associates, serves as a great explainer detailing the differences between a parallel hybrid and a power-split or series-parallel hybrid.
We’re only focusing on these two systems for this article, but check out InsideEVs deep dives on plug-in hybrids, mild hybrids and range-extenders if you want to brush up your knowledge.